The present invention relates to the devices employed for coupling two sections of a conveyor belt. The invention is more particularly concerned with the belt-coupling devices constituted by two rows of fasteners having a generally U-shaped cross-section. These fasteners are intended to be fixed astride the ends of the two belt sections in order to be subsequently united by means of a hinge-pin inserted in the interengaged hinge-knuckles formed by said fasteners.
The basic design of this structure is such that a more or less substantial clearance exists between the hinge-knuckles of the two rows of belt-fasteners as well as between the hinge-knuckles of a predetermined row and the edge of the opposite end of the conveyor belt. Under these conditions, when a belt of this type is employed for transporting bulk materials which include fines such as coal, for example, these fines can pass through the interstices which thus exist in the coupling device. This in fact constitutes a disadvantage since the fines which pass through are liable to penetrate into the journal-bearings and roller-bearings of the guide rollers and drive pulleys of the conveyor belt. This is liable to result in risks of seizure and damage to the installation.
In order to overcome these disadvantages, it has already been proposed to add means for sealing the aforesaid belt-coupling devices as tightly as possible. Thus British patent No. 634,028 describes a coupling device in which provision is made for the addition of a bead of compressible material between the edge of each end of a conveyor belt and the hinge-pin which is engaged within the hinge-knuckles of the two rows of belt-fasteners. By reason of their compressibility, said beads accordingly assume the same shape as the opposite portions of the hinge-pin. However, by reason of the very fact that they are simply fitted within the space located between the coupling pin and the edge of one end of the conveyor belt, said beads are not really fixed in position and are therefore liable to move. Furthermore, as a result of the fact that they are not fixed in position, these beads may become twisted at the time of pivotal motion of the corresponding coupling device and may consequently be damaged in a very short time.
Moreover, the thickness of a bead of this type must be determined according to the thickness of the corresponding conveyor belt. It is therefore not possible to employ the same type of bead for very different belt thicknesses.
For the reasons given above, the invention is directed to a seal which is designed with a view to overcoming the disadvantages set forth in the foregoing and also to ensuring that the seal can be mounted with great ease.